New Zealand operators will be required to notify the Ministry of Foreign Affairs and Trade if they "cause or discover" an environmental emergency.

If they fail to do so they will be required to reimburse any second party which reports the emergency or may be ordered by the High Court to pay the costs to the Environmental Protection Fund, administered by the Antarctic Treaty Secretariat.

Costs will be limited to $US1.5 million ($NZ2.24 million) for environmental emergencies involving a ship and $US4.5m for other emergencies.

The bill was introduced by Foreign Affairs Minister Murray McCully and fulfils New Zealand's obligations under the Antarctic Treaty and yesterday completed its first reading in Parliament.

The liability annex for environmental emergencies was decided in 2005 by the 28th Antarctic Treaty Consultative Meeting and will be in force once all parties approve it.

"Approving the liability annex is an opportunity to highlight and promote, both domestically and internationally, New Zealand's support for a strong environmental protection regime for Antarctica," the bill said.

The law change would require operators to "take preventative measures and establish contingency plans" to reduce the likelihood of accidents harming the Antarctic environment -- many of which happen in areas of New Zealand's search and rescue responsibility.

Compliance costs to New Zealand operators were likely to be covered by insurance already in place, the bill said.

The New Zealand Government, through Antarctica New Zealand, New Zealand Defence Force, Ministry of Fisheries, National Institute of Water and Atmospheric Research, would be liable under the amendment but it already had sufficient insurance to cover the liability.